1. Field of the Invention
The present invention relates to a semiconductor die package having an open cavity that exposes a semiconductor die held in the package to the environment and, more particularly, to an open-cavity semiconductor die package adapted to enable a person to place a finger tip on the semiconductor die.
2. Description of the Related Art
A semiconductor die or chip is an electrical component on which a microcircuit is built. The microcircuits can be interconnected together on the printed circuit board to form larger electrical circuits for use in radios, televisions, compact disk players, and computers, to name just a few. Because the semiconductor die is fragile, it is encased in a semiconductor die package to protect it from the environment. If one were to look inside an electronic device, such as a computer or a compact disk player, one would see one or more printed circuit boards on which semiconductor die packages are mounted and electrically interconnected.
The semiconductor die package includes a housing that holds the semiconductor die and conductive leads or pins that extend from the bottom or sides of the housing. The conductive leads are electrically connected to the semiconductor die within the housing. The outside ends of the leads are soldered to conductive paths on the printed circuit board. This secures the semiconductor die package to the printed circuit board and permits electrical signals to pass between the semiconductor die and other components on the printed circuit board.
In a conventional semiconductor die package, the housing encases the semiconductor die to prevent damage to the semiconductor die from exposure to the environment. The housing may be hermetically sealed, encased in plastic, or otherwise sealed against the environment. Some sealed packages can be opened, without damaging the semiconductor die or the wire bonding between the semiconductor die and the package leads, to allow reworking of the semiconductor die and the leads. These packages are re-sealed after reworking is completed. The process for resealing the package is complex and difficult to accomplish.
In some applications, it may be desirable to expose the semiconductor die to the environment. Some semiconductor dies are designed for use as sensors for sensing, for example, an environmental condition. As a result, at least a portion of the semiconductor dies must be exposed to the environment in order to perform sensing functions. For example, the semiconductor die may serve as a sensor for sensing a person""s fingerprint for identification purposes. In this case, the person""s finger must contact the semiconductor die to enable sensing. Conventional semiconductor die packages cannot be used for such applications because, as noted above, the packages are designed to encase and seal the semiconductor die to prevent exposure to the environment.
The present invention has been made in view of the above circumstances and has as an object to provide an economical semiconductor die package having an open cavity that exposes a semiconductor die held in the package to the environment.
A further object of the invention is to provide a sturdy and reliable semiconductor die package having an open cavity that exposes a semiconductor die held in the package to the environment.
A further object of the invention is to provided an economical method of manufacturing a semiconductor die package having an open cavity.
Additional objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.
To achieve the objects and in accordance with the purpose of the invention, as embodied and broadly described herein, the invention comprises a semiconductor die package having a housing defining a cavity for holding at least one semiconductor die, a plurality of electrically conductive leads, and a cover plate. The housing includes a plurality of insulative side walls and an end plate joined to the side walls. The plurality of electrically conductive leads extend through at least one of the side walls, wherein each of the leads includes an internal lead section extending within the cavity and an external lead section extending externally of the at least one side wall. The cover plate is joined to the side walls opposite the end plate and includes an aperture formed therethrough for exposing to the environment the at least one semiconductor die held in the cavity.
The invention further comprises a method of manufacturing a semiconductor die package comprising the steps of (1) forming a package assembly including a housing defining a cavity for holding at least one semiconductor die and a plurality of electrically conductive leads, the housing including a plurality of insulative side walls and an end plate joined to the side walls and the plurality of electrically conductive leads extending through at least one of the side walls, wherein each of the leads including an internal lead section extending within the cavity and an external lead section extending externally of the at least one side wall; and (2) forming a cover plate for joining to the side walls opposite the end plate, wherein the cover plate includes an aperture formed therethrough for exposing to the environment the at least one semiconductor die held in the cavity.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.